This Project has been designed as a demo application for the Tanzu Applicaiton Platform (TAP). It's microservice architecture is basing on the Newsletter WebUI (newsletter-ui) basing on AngularJS, the Subscription Service (newsletter-subscription) basingon Spring Boot and a PostgreSQL database backend (newsletter-db).
The picture below shows the architecture of the Newsletter Application:
- Newsletter User Interface (newsletter-ui)
- Newsletter User Service (newsletter-user-service)
- Newsletter User Database (newsletter-user-db)
- Newsletter Sailing Service (newsletter-mailing-service)
The Newsletter User Interface is a Web Frontent basing on AngularJS that allows user to signup to the Newsletter. The Interface allows users to register themself to the Newsleter Service and modify or delete their data records afterwards. The Newsleter User Interfaces interacts with the API provided Newsleter User Service to abstract direct connection to the Newsletter User Database.
The Newsletter Subscription Service is the Backend of the Newsletter User Interface and provides an interface (RestFULL) for the application components (newletter-ui or the mailing-service) to interact with cwits API. The the Newsletter User Service uses a PostgreSQL database backend to store persistent user data records. This abstraction allows better to controll who is acessing the service and new service features can be implemented by introducting a new API Version. As well its planned to integrate a circuit breaker in the NEwsleter User Service in a fulure version to prent the service from overloading.
The Newsletter Database acts as backend for the Newsletter Subscription Service and is basing on a PostgreSQL Database running in a container with the same Kubernetes Namespace as the application. The Database is deployed and Managed trough the PostgreSQL Operator running in the default namespace of the same cluster. Morge information about the VMware PostgreSQL Operator can be seen in the documentation VMware SQL with Postgres for Kubernetes Operator.
the Newsletter Mailing Service is a Phyton based application started by the Newsletter Administrator to generation a mass mailing based on the Newsletter registered users provided by the Newsletter User Service API. The Newsletter Mailing Service processes the provided Newsletter template and complement it with the users salutation, email address and unsuscribe-url basing on the registered user-id. Thous malings will then be sent to the configured external Mail Service Provided via SMTP.
Deployment Scenarios The Newsletter application can be deployed local on a Workstation / Laptop which usually the first choise of a developer with the limitation that backensystems (database etc.) requires to be simulated as well as other procects API's which can not be accessed on a local environent. The second deployment option is on top of kubernetes cluster deployed with Tanzu Applicaiton Platform (TAP) that automaticly generate a supply chain depending on the applicaiotn needs.
See Local Deployment